Pampered Poohces Embroider All collars are made of polypro nylon, solid steel D-ring, double lock snap system, adjustable. Sizes available: extra small= 8-10", small= 10-13", medium= 13-16", large= 16-22", extra large= 22"-above. Colors available: Black, brown, royal blue, sky blue, navy blue, red, pink, yellow, orange, teal, purple, grass green, hunter green, lime green.